1. Field
The present disclosure relates to an electrolyte membrane for fuel cells that are operable in high-temperature, non-humidified conditions, a method of manufacturing the electrolyte membrane, a membrane-electrode assembly for fuel cells that includes the electrolyte membrane, and a fuel cell including the membrane electrode assembly.
2. Description of the Related Art
An electrolyte membrane including a polymer film and phosphoric acid is known to be available as an electrolyte membrane for a fuel cell operable at a high temperature of about 150° C. or higher in a non-humidified condition.
As a liquid acid, phosphoric acid likely flows out of the electrolyte membrane during operation, and thus lowers performance of the fuel cell and corrodes other peripheral parts over time. To address these drawbacks, a method of impregnating a polymer film with monomers, instead of phosphoric acid, and polymerizing the monomers is suggested to suppress elution of the phosphoric acid from the polymer electrolyte membrane.
However, an electrolyte membrane impregnated with a monomer has insufficient strength, and is apt to be thin when compressed at high temperatures.
These drawbacks may degrade performance of the fuel cell during operation.
To address these drawbacks, the polymer film may be enhanced by, for example, adding a fiber or inorganic particles when manufacturing the polymer film.
However, electrolyte membranes manufactured using these methods do not have sufficient film strength, and thus there is still a demand for an improved electrolyte membrane.